SI Joint Tensegrity

I am looking forward to participating next month in the orthopedic residency program at The Jackson Clinics in Virginia, in order to gain more knowledge and experience in order to further understand the SI joint and treatment techniques

1. Research performed in 1990 dissected the SI joint and showed large amount of texture and ridges, which was presumed to cause a lot of friction and not allow the SI joint to move.

2. Contrary research by Vukicevic (1991) reports that the pelvic joints maintain joint space even when they are under load and counters the idea that the SI joint has too much friction to move.

Tensegrity is in short and extremely simplified as a model that looks at the reactions that occur at a cellular level. It also supports the idea in #2, that the SI joint has minimal movement, as research in tensegrity has shown that with compression the cells react with increased tension.

Overall the research is outdated and current research is focused on pregnant women who are most likely to have SI dysfunction due to an increase in relaxin and pelvic hypermobility, which is kind of important for having a baby.

Lesson: The SI joint would thus be “floating” and stable (through ligamentous support) simultaneously in order to allow for the transfer of loading forces from the upper torso to the legs, which supports the estimates of 1-2 degrees of rotation and <1mm of translation.

Treatment lesson: Manual techniques are valuable to decrease acute symptoms in patients with SI dysfunction, but ultimately the muscles around the pelvis should be emphasized to increase stability of the pelvis and assist with load transfer between the legs and upper torso. Isometric and eccentric exercises are both necessary to attain these goals.